FWIW Jefferson lined out subject and inserted citizen in an early draft of the Declaration of Independence.
A deep thinker, and no fan of the British and it’s monarchy, Jefferson would certainly have thought through the notion of a substantive analogy between the two concepts of citizenship and subjecthood and found it utter folly.
We obviously can do it looking back with 30/20 hindsight but multiple heavy hitter founding fathers (such as Jefferson, Franklin and Washington) certainly had the distinctions pretty well in hand as early as the beginning of the Revolutionary War.
Adams was drew a parallel between NBC and NBS in a circulated draft of the Treaty of Paris in the early 1780s, but seemingly only for diplomatic purposes.
On the jefferson line edit: good, and bully for him (says i).
alas, the FFs stumbled on not providing a solid definition, and we are left with what we have today plus strict constructionist analysis.
strict constructionist analysis (to be uber strict, i would arbitrarily bar stuff after 1783) would seem to go as follows:
natural born citizen -> (England parallel to) natural born subject -> (English common law) native born -> jus solis “plus” (in practice inclusive of reciprocal situations)
the side effect of reciprocity is that any children born of Americans stationed abroad (McCain, any quasi-illegitimate children fathered by certain illustrious US FFs, etc) would be conferred NBC status along with anyone “born of the soil” in the US.
that is just where my own uber strict interpretation would seem to lead me. different assumptions might well lead to differing results.
I would be very interested in a link to that Adams draft of the Treaty of Paris, if it exists online and you happen to have a link (I will also try to find it by myself). (JMHO, it sounds as if it might be somewhat incidentally relevant one way or another.)